I've been told by engineering customer service at Gesswein, the way
to clean the barrel with stainless steel shot is to run it with
sudsy ammonia for 20 min. Drain, rinse, and repeat until the shot and
barrel seem clean and do not feel greasy. Run a clear water rinse
for 10 min after that. Sometimes ammonia is hard to find in the
grocery store these days, it's too old fashioned and efficient for
new soaps. :-)

One other way to protect the barrel is to first use Rio's pyramid
ceramic medium with deburring compound and take off antiquing such
as liver of sulphur, tarnishing, etc. and rinse well. Then, put in
the burnishing compound with the stainless shot and that keeps the
medium from darkening and the work comes out brighter. I keep two
barrels on hand with the deburring, and two with stainless shot. My
tumbler holds two barrels and it's more efficient this way. Each is
rinsed well, drained through a sieve and left open ready for the next
production items.

Kay, Carin, Ruth - thanks for all of these comments. There is a lotof common points you make and, like I said to Kelley, a good cleanout and empty runs with different water and mild detergent is myfirst plan of action. Did a quick check for ammonia Ruth and lookslike I can get it from Boots here in UK no problem. I'll go with thecoke as I have it at the moment (and I don't even want to think ofits similarities to ammonia!) Thanks folks - invaluable advice. Allyour tips almost make it worth having a disaster at the outset!

I'm hesitant to disagree with engineering customer service atGesswein and i know this sounds goofy but it has always worked forme: I use coca-cola, the beverage. I too use cheapo harborfreight-chicago- tumblers and a couple of times have have the gunkproblem, especially after running deeply patinaed work in it. I justrun the shot in the tumbler for several hours with a can of flat cokein there and rinse it well. Make sure the coke is flat or the barrelwill swell up when it starts tumbling and get so fat that it refusesto roll. Hope this helps...